Irony and perception
The family has no way of explaining Peter's behavior. Instead of showing a person fail whose family is broken or disadvantaged, Peter's story shows a narrative about a character whose perception is radically different than his parent's or the family's perspective. They do not see the way that parental influences shape a child's ability to believe well about themselves and their potential. By instilling high expectations into Peter, the family accidentally sent him into a life of crisis, imposter syndrome, chronic spirals of mental health, and serious feelings of self-disappointment and fear. The family does not understand where it all comes from because they don't see his internal dialogue (dramatic irony).
The law school irony
A person looking for the inciting incident might have a tough time, but it is there. One expects that a letter of acceptance or rejection will serve as the inciting incident, but actually, it is the chronic dilemma caused within Peter's mind by not knowing whether he is accepted or rejected. The inciting incident is a kind of PTSD; he is triggered into childhood feelings of inadequacy and abandonment by the chronic emotional experience of paranoia caused by his inability to know whether he is approved of or not. The connection between law school and his father's approval is also severe.
The bomb threats
There are multiple ironies about the character's decision to make fake bomb threats. The first one is the most obvious; that behavior is extreme and therefore unexpected, especially to his family who was literally just trying to buy him coffee and food and chat with him about his emotions. He is so averse to confrontations in his family that he resorts to unbelievable measures just to avoid such a reckoning—even though he doesn't know what might happen by talking through his feelings. That last part makes this a voluntary experience of dramatic irony; without knowing what his family really thinks, he is left to speculate, and the drama inflames his emotions to extreme levels.
Sexual success
One might read the first part of the book and conclude that this Peter guy has no shot in life. But actually, his deep experience of pain and suffering make him powerful. He is ironically powerful in the sexual game. He cannot overtake his professor in terms of adult responsibility and academic success, but he can steal his wife by being rebellious and truly autonomous. Another irony is that he isn't just attracting anyone; he is attracting a woman who is married to an important authority figure in his life. A psychological interpreter of this novel would have an easy time finding an Oedipal commentary here.
The unlikely fearlessness
So Peter is averse to attention in his family, and he hates feelings of approval and disapproval and the crisis of finding out which one is true about him. One might think he would not really like public attention because perhaps it might signal feelings of worthlessness and panic. In fact, his stage fright is sort of average, and he succeeds when he randomly tries stand-up comedy. He is an unlikely character in this regard because he has no easily-articulated reason for doing comedy, but the painful twist of dark comedy is rewarding to him, and he has suffered enough from disapproval that he has gradually stopped caring what anyone else thinks of him.
